Thread-cutting attachment for automatic lathes.



v J., J. GRANT. THREAD-CUTTING ATTACHMENT FOR AUTOMATIC LATHES.

APPLICATION FILED APR. 17, 1907.

Patented-Au 31, 1909.

7 v Invemiazrii z'z'laesses J. J. GRANT.

THREAD CUTTING ATTACHMENT FOB AUTOMATIC LATHBS.

APPLIGATIOI FILED APR. 17, 1807.

Patented Aug. 31. 1909.

3 SHEETS-SHEET 2.

Witness es.

6 y &/ M y a a dis al a 7M. T-GW J. J. GRANT. THREAD CUTTING ATTACHMENT FOR AUTOMATIC LATHES. APPLIOATIOI rmm APB. 11,1901.

932,607. Patented Aug. 31. 1909.

8 BHEBTB-BHBBT 3.

III

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.QPatented Aug. 31,1909.

A naaonmma iu 17, 1907. serial m. .saa,sv2.

To all whom it may Be'it known that 'LJQRNJ. GRANT, a citizen of the United States, resident of Cleves land, county of Cuyahoga, and State of Ohio, have invented a new and useful Im provement in Thread-Cuttingl Attachments or Automatic Lathes, of whic .the following is a s ecification, the principle of the invention eing herem explained and the best mode in which I have conte'm lated ap lying that principle, so as-to istinguls it from other inventions. My invention relates tothread cutting devices andhas particularv regard to thread cutting attachments for use on automatic turret athes such as screw-machines and the In the form here presented such atas designedfor use in f h an automatic turret lathe 0 t et 'esetu inm pen ingapp ication filed Ap i' il 28, 19 66, Seiial No. 314,197. The object of said invention is the rovision of a thread cutting device of the 0 arwhere the various adjustments required to invention effect the, cuttin lengths and easlly eifecte Y To the accomplishment of these and. related ends, said mvention consists of means hereinafter fully described and particularly pointed out in the claims.

he annexed drawings and the following description set forthin detail certain mechanism embodying the invention, such disclosed means constituting,,however,-but one ofvarious mechanical forms in which the principle of the invention may be used.

In said annexed drawings :.Figure 1 re resents a front elevation of one end of a lat e of the eneral type referred to above,- whereon is shown mounted a tapping device embo'dying the rinciples-of construction of my 1g. 2 1s partly an end elevation of ,threads of different dpitc es may. be .quickly. and

and part1 and attac ed tapping device; Fig. 3 is a longitudinal cross-section on a larger scale of a portion of the die-shaft and certain appurte-- nant parts; and Fig. '4 is a development of the'cam utilized to effect movement of oer.-

- tac j ity of tool-holding sockets 0, four, 1n number ,Such stock is suitably hel 2. Such rear end extends some yond standard B and between a collar 6, se-

a cross-section of such machine tain parts connected with such ent. Ofthe lathe or screw machine, as has been tapping atindicated, only one end is shown, thisillustrated portion comprising the machine frame A, integral with which is formed the tool head 0. In such head are provided a plural- 6 0 as shown, which are adapted to receive, either fixedly or rotatably, as the case may be, the various tools utilized in performing the desired operations upon the stock.

in a rotatable spindle, not shown, of the usual type that is adapted to be successively presented to the several tools secured in-the tool head as is fully described and set forth in mypending application above referred to. Operation 0 the various rotatable tools in such tool head, as also that of the screw-holdin spindle in the manner just set forth, is ha from a suitableback-sh-aft D, here shown as bein tubular, that is 'ournaled in bearings d therefor rovideti on the rear side of machine be A. Such back shaft is in turn driven from a second shaft D upon which is mounted a driving ulley d.

The shaft B, to t 0 forward end of which the threading tool, not shown, is designed to be attached, is both longitudinally slidably and rotatably mounted in one of the u per tool-receiving sockets c in the head its rearwardly rojecting end being supported in a standard B removed some dlstance from the fixed tool head 0 and detachably secured on the top of the machine frame, Flgs. 1 and distance becured on its extreme end ard B'is a spring B, the obviousl to normally retract suchdie-shaft as:I shali denominate the same, for the sake of convenience. Immediately ad'oining the other side of standard B is rotatablv mounted upon shaft B a gear I) that in the operation of the machine is intended to be continuously driven by a gear b? mounted upon drive shaft D. To eflect operative connection of such rotatably mounted ear I) with the die-shaft a clutch collar B iseathered on the latter intermediate of the tool head C and said gear I). The detailed construction of 105 clutch collar B is clearly shown in Fig. 3,

by nut b, and standfunctionof which is whereit will bejseen to comprise-a collar '.propefbearingsat one end a clutch pin. b!

" that is adaptedto ing' formed adapted to receive the shiftin 'sitionr- 'That of the second eng be to connect the shaft with engage a correspondnsa pin t l rally-. p je i g f s r i.- One, of said pins, 6 asshown, .18 desirably resiliently mounted; in order to obviate any danger o'fthe members becoming locked in case the ins meet-end on. Such collar is also providedwith-an encircl' groove 6 evice hereafter-to be described. Said co lar is furthermore formed with a bore of twodiiferent diameters,'the portion of'larger diameter-bein the end removed from the clutch end of the collar; In such enlarged bore is slidably mounted a sleeveb"; being retained against displacement by a nut Interposed between said sleeve b and the offset between the larger and smaller bore portions within the collar is a spring b, that 1t will be seen resiliently retains said sleeve in its outermost position.

Intermediate of lutch collar B and tool head. C is aratchet member B fixedly mounted upon said shaft B but longitu'dr nally adjustable therealong, a set screw b being provided to secure it at the desired place on'the-shaft. Clutch collar B is designed to have a range of movement sufficient to adapt it in one position to effect the engagement of resiliently su ported sleeve 1).

with ratchet member B an in another posi tion to effect the en agement of clutch pins b b. The effectof file first engagement will obviously be to advance shaft B against spring B that it will be recalled, serves normally-to retain thesame inits retracted pogtement will t e driving gear I). j

Ratchet member B and thereby shaft B is designed to be'normally held against rotation by means of'theenga ement therewith of an'oscillatorily mounte pawl E-,- Figs. 1

sections e e, the former being screw-threaded to prevent its rotation,

and 2. Said pawl is normally retained in position to thus engage and hold ratchet member B? by means; of a rod E reciprocably mounted'in a suitable hollow support a provided for this purpose on the top of machine frame A; Rod E comprises two within the latter whereb adjustment of the length of said rod as aw ole is to be readily ha .by simply rotating the 'upper section relatively to t ably feathered in support a, see Fig. 2, so as A j am nut e serves ock the section's against-relative rotation once-the desired adjustment has been effect ed. Connection between rod section a and pawl Eis had by providing the latter with a segmental worm gear c wherewith a'worm e on the former is designed to'mesh; The weight of the .rod E is amply suflicient to maintain the pawl in the engagement aforeably mounted on a bracketa detachabl secured to the top of machinenjame 'AL e lower, which latter is suit said Upwardactuation of :such rod ,1 mowever, it will be .clear, -w:ll release the ratchet member therefrom. o Pawl E is 'rovided order that, its securemetention ofthe ratchet.

member B will not .be' afiectedfby the shiftingxofithe latterwhetherdire to; a" variationin its adjustment, or to the advance"movement of the shaft whereon said ratchefirnemberis' mounted. Reciprocation of clutch collar B is had by means ofan oscillatoryarmF suit-' uch arm bears at its upper shes-sensed fdrk f I that rests in the'encirclinggrove b in the collar whereby it will be seen the-sliifting-of the latt'er is effected without; h'terfering with its'rotation along with'shaft*-B-.-j F" U ward movement' of rod E and "also osci ation of .clutch' collar actuatingarm'rF is had-by means of 'a combined} cam 'H,' Fi' 2 and 4. Suchrodand'armare respective y provided with rollers e and? designed to be engaged at the proper time by the cam 'surfaces of-said drum; Thelatter', a development' of-which appears inFig. 4 of refer-'- ence; is designed to effect movement of the rod and of the arm so as to'%oducethe-following actuation-of die-shaft Inthe nor-' mal, or inoperative; position of the shaftthe parts occup relative ositions substantially as shown in g; l of t e drawings; In other words clutch collar B is in" engagement with neither driving member I) nor ratchet member B; and rodE is left free to hold such ratchet memberagainst rotation; In this state of affairs spring B is also-clearly free to hold said shaft B in its retracted osition.j Assuming now the stockthat isto eoperated upon by the tapping tool to be properly positioned in alinement with shaft B, the cam H will have been so timed that 'camr face h thereon engages roller f of arm F to move collar B into engagement with ratchet member JB and thereby advance the die-shaft u' on the stock at a rate determined by the c aracter of the cam surface. This forced advance is intendedto continue long. enough only to startthe thread; the tool feeds itself after once started-.- Since such stock is rotated by the stockspindle while the die shaft still remains held against any rotation, the obvious effect will be the cutting of a thread in the stock; thelength of; which will be-determined by the release -of ratchet member B upomthe rupward actuation of rod 1*].

Suchactuationis had-by engagement of cam surface h and rollers and can be accurately timed b'y-varyin the length of the'rod in the manner-before: ascribed, thecam in; question'being longer than necessaryto effect release' in any: particular position: Ofufldjllfltmerit:- -Upon release of" the die shaft the latter-rotates. freely with the stockuntil clutch collariB ds shifted linl the reversedi- 7 pins b b into engagement.

esaeo'r rectionfrom that just-set forth b the engagement offlcam face h -with ro er f" on arm F, the eflect of which is to bring clutch The ratio of gear I) to the stock in the spindle is such that upon this-engagement a rotation of die shaft B- is effected in the same direction as, but at a higher rate of speed than, that of the stock in the spindle. Accordingly the result of By the worm. and 'worm gear connection shown between the rod and 'awl E instead of a lain rack and pinion, t e facility 'with whic this ad'ustment is to be had is much increased. T eforward movement of the die-shaft isregulated in the same fashion independently of the throw of the cam face h.

The latter need not be changed, for by merely Y moving the ratchet member one wayaor the otheralong the die-shaft, such advance is correctly timed. This timing' however, need not be more than approximate in its f exactness, for any forward movement of clutch collar B after the shaft is'onee free to rotate results simply in additional com ression of the spring 1) whereby sleeve b 1s resiliently supported. This sprin serves the further function of adjustin t e advance movement imparted to the col ar by the cam, which it is not designed should require to be changed, to the reqpirements of the particular thread being cut. Inv other words-this spring constitutesa compensating means, so t at if during the brief engagement of the collar with the ratchet member, the former is advanced more rapidly than the threading tool requires, having re ard to the fineness of the thread being cut, t e spring will simply be compressed. Injury to stock and cutting tool, both, is thus prevented. The object in housing the spring in question in the manner shownin Fi 3 is not merel to add to the neatness of t e construction, ut also to hold the spring in question under an initial degree of tension suflicient to insure the prompt starting of the threading tool upon its engagement with the stock.

Standard B and bracket a'being both detachabl mounted on themachine frame A, it will e evident that the threadin device in the form here illustrated is in trut an attachment and as such articularly adapted for use with turret lat es where it is frequently desirable to make changes in the tools. The supports just referred to .upon

removal carry with them the die-shaft and v all appurtenant parts, leaving the tool head, as also top of the machine frame, clear for the attachment of such other tool as may be re-' quired in the stead of the threading tool.

It should possibly be noted that while the device as shown and described is adapted to the cutting of right-hand threads, by slight modifications, that are easily made, b61115 known in the art, such device can be adapts forllthe cutting of left-hand threads just as we ()ther modes of a plying the principle of my invention may e employed instead of the one explained, change'being made as regards the mechanism herein d1sclosed,'providedthe. means stated by any. one of the following claims or the e uivalent of such state means be em 10 cal.

I therefore particu lar y point out and distinct] claim asmy invent1on:

- 1. n mechanism of. he class described, the combination of a-die-shaft -both longitudinally slidably and rotatably mounted ;v

means tending to retract said die-shaft; a. member transversely movable with respect "to said die-shaft adapted normally to engage and hold the same against rotation; means adapted positivel to withdraw said holding member; and ot er means inde endent of said withdrawing means ada te longitudinall to advance said vdie-s aft and ositive y to rotate the same, substantial y as described.

2. In mechanism of the class described, the combination of a die-shaft both longitudinallyslidably and rotatably mounted; means tending to retract said shaft a driving member rotatably mounted upon said shaft; a ratchet member fixedly mounted thereon; a shiftable member non-rotatably mounted on said shaft between said ratchet and driving members and ada ted to engage the former to advance said shaft upon the work, and the latter to operatively connect the combination of a die-shaft both longitudinally slidably and rotatably mounted; means tending to retract said shaft; a driving member rotatably mounted upon said shaft; a ratchet member fixedly mounted u on said shaft but longitudinally adjustable t erealong; a. pawl ada ted to engage said' ratchet member to hol said shaft against rotation; and a collar splined on said shaft between said ratchet and driving members and adapted to engage the former to advance said shaft upon the work, and the latter to operatively connect the same with said shaft. 4. In mechanism of the class described, the combination of a die-shaft both longi- I .tudinfllly slidably and rotatably mounted i means-tending to retract said shaftr. a driv a ing member rotatably mounted upon said rotation; means for controllin said pawl adapted toreciprocate sai a collar splined on said shaft etween'said ratchet and driving members-and provided with a'clutch adapted to'engag'e the latter; resilient means interposed between said col larand said ratchet member; and Q eans adapted to shift said collar alternately 1 to engagement with said ratchetand driving mem r 5. In mechanism 'of' the class described, the combination of'a die-shaft both longitudinall slidably and rotatably mounted; means ten g to retract. said'i'shaft; a driving member rotatably mounted upon said shaft a ratchetmember fixedly mounted on sai shaft but longitudinally adjustable there? I along; a pawl adapted to engage said ratchet v member to hold said' s'haft against rotation a reciprocable rod connected with said pawl and normallyv retaining the same in such: 61% gagement; a cam adapted to reciprocate said rod; a'coll'ar splined on said shaft be tween said-ratchet and driving members and provided with-a clutch adapted to engage the latter; resilient means interposed between said collar and said ratchet member; and cam-actuated means adapted to shift said collar alternately into engagement with said ratchet and driving members.

6. In mechanism of the class described, the combination of a die-shaft both longitudinally slidably and rotatablymounted; means tending to retract said shaft; -a driving member rotatably mounted upon said shaft; a ratchet member fixedly mounted on said shaft but longitudinally adjustable therealong; a pawl ada ted to engage said ratchet member to hol said shaft against rotation; .a reciprocable rod adjustably con-P nected with said pawl and normally retain-r ing the same in such enga ement; a cam rod; a collar splined on said shaft between said ratchet and driving members and provided with a clutch adapted to engage the latter resilient means interposed between said collar. and said ratchet member; and cam.- actuated, means adapted to shift said collar alternatel intovengag'ement with said ratchet and riving members.

f 7. In mechanismof the class described,

the-combination of adie-shaft both longitudinally slidably and rotatably mounted; means tending to retract said shaft; a driving member rotatably mounted .upon said shaft; a ratchet member fixedly mounted on said shaft but longitudinally adjustable therealong; a pawl oscillatorily mounted and riving mem ers,

.sprin tending to retract said mem er rotatably mounted upon said shaft" asam and adapted to engage said ratchetmember to hold said shaft a ainst rotation, said pawl bearinga segmenta gfar; a reciprocablerod of adjustable len h earing amok in .mesh with said gear, t ereby normally'retaining said pawl in engagement with said ratchet; a-cam' adapted to reciprocate said rod; a collar splined: on said shaft between said ratchet and driving members and provided with a clutch adapted to engage the latter; resilient means interposed between said'colliar and said ratchet member; and mum actuated means adapted to shift said col-- lar alternately into engagement with said ratchet a'nddriving members.

8. In" mechanism of the class described,

'the combination of' a die-shaft both longitudinally slidably and rotatably mounted; means tending to retract said shaft; a driving member rotatably mounted'upon said shaft; a ratchet member fixedly mounted" on said shaft but longitudinall ,adjustable therealong; a pawl oscillatori mounted and adapted to engage said ratc et member I to hold said-shaft against rotation, said pawl bearing a segmental worm gear; a reciprocable rod comprising two sections, one be adjustably mounte within the other an bearing a worm in mesh with said gear whereby said pawl is normally retained in engagement with said ratchet; a cam adapted to reciprocate said rod; a collar splined on said shaft between'said ratchet and driving. members and provided with a clutch adapted to engage the latter; resilient means interposed between said collaij and said ratchet members; and cam-actuated means. adapted to shift said collar alters natel into enga ement with said ratchet 9. In mechanism of the class described,

the combination of a die =shaft both longitu-- mounted; a

ara'tchet member fixedly mounted on sai shaft but lon 'tudinally adjustable there? along; a paw oscillatorily mounted and ada ted to engage said ratchet .to hold said sha t against rotation, said pawl bearing a segmental worm, gear; a reciprocable rod com rising two sections one screw-threaded in t e other and bearing a worm inmesh with said gear, whereby said pawl is nor? mally retained in engagement with said ratchet; a collar splined on said shaft between said ratchet and driving members and provided with a clutch adapted to en age the latter; resilient 'means interposed ietween said collar and said ratchet member; anostcillatory arm adapted to shift said collar; and a cam adapted both to swing said arm and to reciprocate said rod.

10. In mechanism of the class described, the combination with a die-shaft, of means the combination with a die-shaft, of means ada ted to retain the same against rotation, sai means comprising a ratchet member fixedly mounted upon said shaft, a pawl oscillator1ly mounted and adapted to engage said ratchet member to hold the same agamst rotation, said pawl bearing a segmental gear; a reciprocable rod of adjustable length bearing a rack in mesh with said gear, thereby normally retaining said pawl in engagement with said atchet; and a cam adapted toreciprocate said rod to release said ratchet 'member, such release being timed by length of said rod. 1

1.2. In mechanism of the class described, the combination with a die-shaft, of means ada ted to retain the same against rotation,

sai means comprising aratchet member fixedly mounted upon said shaft, a pawl oscillatonl mounted and adapted to engage said rate at to hold the same a ainst rotation,said

- pawl bearing a segmenta worm gear; a' reciprocable rod comprising two sections, one bemg screw-threaded in the other and bearmg a worm in mesh with said gear, whereby Attested bymember, such release being timed by length,

of said rod.

13. In mechanism of the class described,

the combination with a die-shaft, of means for advancing the same upon the work, such means comprising a member longitudinally adjustably fixed upon said shaft, a collar slidably mounted u on said shaft, a cam-actuated arm ada te to shift said collar into engagement wit said member to thus ad vance the shaft, and a resiliently sup orted sleeve borne by said collar and adapte to actually contact with said member.

14. In mechanism of the class described, the combination with a die-shaft, of means for advancing the same upon the work, such means com rising a member longitudinally adjustably ed upon said shaft, a cam-actuated arm ada ted to shift said collar into ongagement wit said member to thus advance the shaft, a sleeve slidably mounted in such collar and held against disenga ement therefrom, said sleeve being ada te upon movement of such collar to actua y contact with said fixed member, and a s ring interposed between said collar and s eeve to resiliently support the latter, said spring being held under an initial degree of'tension.

. Signed by me, this 19th day of March 1907.

' JOHN J. GRANT.

D. T. DAVIES,- JNo. F. OBERLIN. 

